Funasaka S, Kumakawa K
Department of Otolaryngology, Tokyo Medical College, Japan.
Audiology. 1988;27(2):99-108. doi: 10.3109/00206098809081580.
In this new tympanometric system, air pressure in the external meatus is kept constant at either -200 daPa or 0 daPa. The frequency of the probe tone is swept from 220 to 2,000 Hz (or 2,500 Hz, if necessary) in 4 s. During this frequency sweep, sound pressure in decibels and phase angle in degrees in the external meatus are sampled and the differences in sound pressure and phase angle measured at -200 and 0 daPa pressures are computed. These results are figured as a frequency-sound pressure curve and a frequency-phase angle curve. From the study on 8 fresh human cadaver temporal bones, four parameters in these curves are selected by discriminant analysis to provide diagnostic criteria: the minimum value and the 0-cross frequency of the frequency-sound pressure curve and the maximum value and its frequency of the frequency-phase angle curve. Normal parameters were determined in 50 normal ears. Evaluation of 40 patients with ossicular disorders revealed that 10 out of 12 cases of ossicular discontinuity and 5 out of 6 cases of malleus and/or incus fixation were correctly diagnosed. For stapes fixation, the diagnosis was correct in 12 out of 22 ears. This system is useful in the clinical diagnosis of ossicular disorders, producing a collection of curves and parameters that are distinctively different for the ossicular discontinuity and the ossicular fixation.
在这个新的鼓室声导抗测量系统中，外耳道内的气压保持恒定在-200 daPa或0 daPa。探测音的频率在4秒内从220 Hz扫频至2000 Hz（如有必要，可扫频至2500 Hz）。在这个频率扫描过程中，外耳道内以分贝为单位的声压和以度为单位的相位角被采样，并计算在-200 daPa和0 daPa压力下测量的声压和相位角的差值。这些结果被绘制成频率-声压曲线和频率-相位角曲线。通过对8个新鲜人尸体颞骨的研究，通过判别分析从这些曲线中选择四个参数以提供诊断标准：频率-声压曲线的最小值和零交叉频率以及频率-相位角曲线的最大值及其频率。在50只正常耳朵中确定了正常参数。对40例听骨链疾病患者的评估显示，12例听骨链中断病例中有10例以及6例锤骨和/或砧骨固定病例中有5例被正确诊断。对于镫骨固定，22只耳朵中有12只诊断正确。该系统在听骨链疾病的临床诊断中很有用，可生成一系列曲线和参数，这些曲线和参数对于听骨链中断和听骨链固定明显不同。
